Method for harvesting solar energy

ABSTRACT

A photovoltaic system includes a photovoltaic cell including a sun tracker, a top surface configured to generate electrical energy from the incident sunlight, and a bottom surface configured to thermally dispel heat generated by the photovoltaic cell; at least one mirror including a reflective surface; a plurality of actuators securing the at least one mirror the photovoltaic cell; at least one actuator pump connected to the plurality of actuators and configured to extend or retract the plurality of actuators and adjust the distance of the at least one mirror from the top surface; a heat exchanger thermally coupled to the bottom surface of the photovoltaic cell; and a fluid pump connected to the heat exchanger and configured to circulate the fluid through the heat exchanger.

BACKGROUND Field of the Invention

The present disclosure is related to a method and apparatus forharvesting sunlight using a photovoltaic system with adjustable mirrorsand an integrated cooling system.

Description of the Related Art

Although solar power plants have been in existence for many years, theelectricity generated by them has been costly in comparison toalternative generation methods such as coal or natural gas. This problemhas been compounded by the shortage of solar-grade silicon that hasbecome expensive. A solution to compensate for the high production costis to improve the PV efficiency by reducing the amount of material usedand maintaining the sun's rays on to the surface of the photovoltaicpanels during the daytime.

Current methods include concentrating the sunlight onto a smaller solarcell area and rotating the panel to track the sun. Regarding the formersolution, reducing the material used in constructing the solar cellsaves on cost, but concentrators can utilize complex optical systemsthat require expensive lenses and curved mirrors. Furthermore, rotatingthe entire panel assembly can lead to increased operation costs due tothe need to move a heavy structure (both the full-sized solar cellassembly and the smaller solar cell with a large concentrator assembly).Thus, a solution that can track the sun's movement to direct sunlightonto the panel while being lightweight can improve efficiency whilemaintaining low operational costs. Furthermore, performance degradationfrom deposited surface debris can be mitigated via a solution thatprotects and cleans the solar cell surface.

As described in US Patent US20080314438A1, incorporated herein byreference in its entirety, an energy device includes a solarconcentrator that concentrates at least 20 suns on a predetermined spot,a solar cell positioned on the predetermined spot to receiveconcentrated solar energy from the solar concentrator, and a waterheater pipe thermally coupled to the solar cell to remove heat from thesolar cell.

As described in U.S. Pat. No. 5,959,787A, incorporated herein byreference in its entirety, a solar panel is covered with a concentratingcoverglass which allows efficient power generation for providing higherspecific powers by space power arrays. A preferred frustoconical lensachieves a concentration ratio of about 4.5 at a thickness of about 1.0mm. Efficient space power arrays with relatively wide tracking angletolerance of up to about ±5° using these coverglasses permit heavierpayloads in the satellite's operating systems over traditional satellitedesigns.

As described in US Patent US20090283144A1, incorporated herein byreference in its entirety, a solar panel assembly includes a solarconcentrating mirror for enhancing the use of solar collection devices.The concentrating mirror includes a multilayer optical film and acompliant UV protective layer. The concentrating mirror reflectsspecific bandwidths of electromagnetic energy to the solar cell whileeliminating or reducing undesirable bandwidths of electromagnetic energythat may degrade or adversely affect the solar cell.

As described in U.S. Pat. No. 5,374,317A, incorporated herein byreference in its entirety, a solar electric power system includesmultiple reflectors to concentrate sun light onto a panel ofphotovoltaic (PV) cells. The power system, consisting of multiplereflectors, mounted PV cells, and a heat dissipation component, ismounted on a tracker that keeps the system directed to the sun.

As described in US Patent US20100282315A1, incorporated herein byreference in its entirety, a solar collector includes an elongatedcross-sectionally V-shaped beam where the sidewalls are reflective andcollect incident sunlight via deflecting the rays down the beam sidewalls toward the beam web.

In many solar energy harvesting designs, energy loss from performanceinefficiency and operational costs can originate from multiple sources,including moving a heavy structure to track the sun's path, increasedoperating temperature of the photovoltaic, and deposition of debris onthe photovoltaic surface. A solution can be designed with a lightweightalternative means of redirecting and maintaining sunlight on thephotovoltaic (PV), a temperature regulation system for the PV, and amethod of cleaning and protecting the PV surface.

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

SUMMARY

The foregoing paragraphs have been provided by way of generalintroduction, and are not intended to limit the scope of the followingclaims. The described embodiments, together with further advantages,will be best understood by reference to the following detaileddescription taken in conjunction with the accompanying drawings.

According to one or more embodiments of the disclosed subject matter, aphotovoltaic system includes a photovoltaic cell including a sun trackerincluding circuitry configured to determine an angle and an intensity ofincident sunlight, a top surface configured to generate electricalenergy from the incident sunlight, and a bottom surface configured tothermally dispel heat; at least one mirror including a reflectivesurface and being disposed adjacent to the top surface of thephotovoltaic cell; a plurality of actuators each having a first end anda second end, wherein the first end is attached to the photovoltaic celland the second end is attached to the at least one mirror; at least oneactuator pump connected to the plurality of actuators and configured toextend or retract the plurality of actuators and adjust the distance ofthe at least one mirror from the top surface; a heat exchanger disposedadjacent to and thermally coupled to the bottom surface of thephotovoltaic cell, wherein the heat exchanger is filled with a fluid;and a fluid pump connected to the heat exchanger and configured tocirculate the fluid through the heat exchanger.

According to another embodiment, the system can further include a motorattached to the second end of the plurality of hydraulic actuators,wherein the at least one mirror is secured to the motor and the motor isconfigured to rotate the at least one mirror, and a radiator connectedto the heat exchanger and the fluid pump, wherein the fluid pump isconfigured to circulate fluid through the heat exchanger and theradiator, and the radiator is configured to cool the circulated fluidvia thermal exchange with an external medium.

In another embodiment, a method of harvesting sunlight in a photovoltaicsystem includes determining, via circuitry of a sun tracker of aphotovoltaic cell, an angle and an intensity of incident sunlight,wherein the photovoltaic cell includes a top surface configured togenerate electrical energy from the incident sunlight and a bottomsurface configured to thermally dispel heat; adjusting a height of atleast one mirror based on the angle and the intensity of the incidentsunlight such that the incident light is reflected by a reflectivesurface of the at least one mirror onto the top surface of thephotovoltaic cell, wherein the at least one mirror is disposed adjacentto the top surface of the photovoltaic cell; adjusting a rotation angleof the at least one mirror based on the angle and the intensity of theincident sunlight such that the incident light is reflected by thereflective surface of the at least one mirror onto the top surface ofthe photovoltaic cell; generating, via the top surface of thephotovoltaic cell, electrical energy from the incident sunlight that isreflected onto the top surface of the photovoltaic cell by thereflective surface of the at least one mirror; and dispelling, via thebottom surface of the photovoltaic cell, heat generated by thephotovoltaic cell.

In another embodiment, the method further includes detecting, using thephotovoltaic cell, that the intensity of the incident sunlight is belowa predetermined threshold; adjusting, using the plurality of actuators,the height of the at least one mirror; and rotating, using the motor,the at least one mirror to induce turbulent air flow to clean the topsurface of the photovoltaic cell of any deposited foreign matter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a schematic of the photovoltaic system according to one ormore aspects of the disclosed subject matter;

FIG. 2A is a side-view schematic of the photovoltaic system mirrorsmounted on motors and rotated to redirect sunlight according to one ormore aspects of the disclosed subject matter;

FIG. 2B is a side-view schematic of the photovoltaic system mirrorsmounted on multiple actuators and angled to redirect sunlight accordingto one or more aspects of the disclosed subject matter;

FIG. 3A is an isometric-view schematic of the photovoltaic system mirrorwith expandable side mirrors according to one or more aspects of thedisclosed subject matter;

FIG. 3B is a front-view schematic of the photovoltaic system mirror withexpandable side mirrors according to one or more aspects of thedisclosed subject matter;

FIG. 3C is a top-view schematic of the photovoltaic system mirror withexpandable side mirrors according to one or more aspects of thedisclosed subject matter;

FIG. 4A is a side-view schematic of the photovoltaic system with themirrors oriented to reduce a shadow on the photovoltaic cell accordingto one or more aspects of the disclosed subject matter;

FIG. 4B is a side-view schematic of the photovoltaic system with themirrors oriented to protect the surface of the photovoltaic cellaccording to one or more aspects of the disclosed subject matter;

FIG. 4C is a side-view schematic of the photovoltaic system with themirrors rotating to clean the surface of the photovoltaic cell accordingto one or more aspects of the disclosed subject matter; and

FIG. 4D is a side-view schematic of the photovoltaic system with themirrors moving upwards and downwards to clean the surface of thephotovoltaic cell according to one or more aspects of the disclosedsubject matter.

DETAILED DESCRIPTION

The description set forth below in connection with the appended drawingsis intended as a description of various embodiments of the disclosedsubject matter and is not necessarily intended to represent the onlyembodiment(s). In certain instances, the description includes specificdetails for the purpose of providing an understanding of the disclosedsubject matter. However, it will be apparent to those skilled in the artthat embodiments may be practiced without these specific details. Insome instances, well-known structures and components may be shown inblock diagram form in order to avoid obscuring the concepts of thedisclosed subject matter.

Reference throughout the specification to “one embodiment” or “anembodiment” means that a particular feature, structure, characteristic,operation, or function described in connection with an embodiment isincluded in at least one embodiment of the disclosed subject matter.Thus, any appearance of the phrases “in one embodiment” or “in anembodiment” in the specification is not necessarily referring to thesame embodiment. Further, the particular features, structures,characteristics, operations, or functions may be combined in anysuitable manner in one or more embodiments. Further, it is intended thatembodiments of the disclosed subject matter can and do covermodifications and variations of the described embodiments.

It must be noted that, as used in the specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the context clearly dictates otherwise. That is, unless clearlyspecified otherwise, as used herein the words “a” and “an” and the likecarry the meaning of “one or more.” Additionally, it is to be understoodthat terms such as “left,” “right,” “top,” “bottom,” “front,” “rear,”“side,” “height,” “length,” “width,” “upper,” “lower,” “interior,”“exterior,” “inner,” “outer,” and the like that may be used herein,merely describe points of reference and do not necessarily limitembodiments of the disclosed subject matter to any particularorientation or configuration. Furthermore, terms such as “first,”“second,” “third,” etc., merely identify one of a number of portions,components, points of reference, operations and/or functions asdescribed herein, and likewise do not necessarily limit embodiments ofthe disclosed subject matter to any particular configuration ororientation.

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views.

FIG. 1 illustrates an exemplary photovoltaic (PV) system 100 forharvesting sunlight according to one or more aspects of the disclosedsubject matter. The PV system 100 includes a PV cell 105 to which atleast one mirror 110 is attached to the PV cell 105. The at least onemirror 110 can represent one or more mirrors in the PV system 100. Asshown in FIG. 1, the PV system 100 can include two mirrors, which willbe the configuration referred to herein for convenience. Each of themirrors 110 can be attached to the PV cell 105 using a hydraulicactuator 115 fitted with a DC motor 120, wherein the hydraulic action ofthe hydraulic actuator 115 can be controlled by an actuator pump 125 andthe DC motor 120 can be configured to rotate the mirrors 110. A heatexchanger 130 can be attached to the PV cell 105 and fluid can becirculated through the heat exchanger 130 via a fluid pump 135 and intoa radiator 140 to cool the fluid.

The PV cell 105 can include a sun tracking device with circuitryconfigured to determine an angle and an intensity of incident sunlightand adjust the mirrors 110 to reflect solar radiation onto the PV cell105. The PV cell 105 can include a top surface configured to operateusing the photovoltaic effect wherein incident or reflected solarradiation can be absorbed by the PV cell 105 and converted to anelectric current. The generated electric current can be routed to myriaddestinations depending on the intended use, for example, to a separatebattery for storage, fed directly back into a power grid, or usedimmediately by an electrically attached device requiring electricalcurrent for operation. The PV cell 105 can include a bottom surfaceconfigured to dispel heat generated by the incident sunlight and PV cell105 operation. In an alternative aspect, the PV cell 105 can be a solarthermal cell, wherein absorbed solar radiation is converted to thermalenergy and, for example, used to heat a liquid such as water to producesteam and power a turbine to generate electricity. The PV cell 105 canadopt a shape to most optimally cover a predetermined area. For example,the shape can be circular, square, or rectangular (as shown).

The mirrors 110 can be a panel of reflective material configured toreflect solar radiation onto the PV cell 105. The reflective materialcan reflect wavelengths in the range of the electromagnetic spectrum forsolar radiation, which can include ultraviolet, visible light, andinfrared radiation. For example, the mirror can exhibit specularreflectance of wavelengths from 100 nm to 3,000 nm, preferably 150 nm to2,500 nm, or 250 nm to 2,000 nm. The mirrors 110 can be a flat or nearlyflat rigid structure coated with a reflective material. The shape of themirror can include circular, square, or rectangular (as shown).Non-limiting examples of materials for the rigid structure of themirrors 110 can include at least one of glass fiber-reinforced polymer,aramid fiber-reinforced polymer, basalt fiber-reinforced polymer, carbonfiber-reinforced polymer, metal, metal alloy, and polymer. Non-limitingexamples of materials for the coated reflective material can include atleast one of tin(II) chloride, silver, aluminum, copper, and reflectivepaint, such as those impregnated with reflective structures such asglass or silver beads. The mirrors 110 are disposed above the topsurface of the PV cell 105 and sized such that the mirrors 110 can coverall or nearly all the surface of the PV cell 105 when the mirrors 110are rotated and laid flat. As shown in FIG. 1, the two mirrors 110 eachcover approximately one half of the PV cell 105, and the mirrors 110 aredisposed length-wise adjacent to and along the long edges of the PV cell105.

In an alternative embodiment, the mirrors 110 can be disposedlength-wise adjacent to and along the short edges of the PV cell 105,wherein the mirrors 110 can adopt less elongated, more square shapes andeach cover approximately one half of the PV cell 105.

In another embodiment, the mirrors 110 can be configured to increase thereflective area via additional reflective panels. FIG. 3A-3C illustratesan at least one expandable mirror 310 according to one or more aspectsof the disclosed subject matter. The at least one expandable mirror 310can include a first side, the first side being reflective, and a secondside opposite the reflective side. The at least one expandable mirror310 can include at least one side mirrors 310 a, for example two sidemirrors 310 a (as shown), that include a reflective side and anon-reflective side, and are configured to reposition outwards to aposition flanking the at least one expandable mirror 310. For example,the side mirrors 310 a can be disposed in a first position behind the atleast one expandable mirror 310 wherein the reflective side of the sidemirrors 310 a is adjacent to the second side of the at least oneexpandable mirror 310. The side mirrors 310 a can slide laterallyoutwards from the first position behind the at least one expandablemirror 310 to a second position flanking an edge of the at least oneexpandable mirror 310 wherein the reflective surface of the side mirrors310 a adds to the total reflective area of the at least one expandablemirror 310. Alternatively, the side mirrors 310 a can be disposed in afirst position behind the at least one expandable mirror 310 wherein thenon-reflective side of the side mirrors 310 a is adjacent to the secondside of the at least one expandable mirror 310. The side mirrors 310 acan fold outwards to a second position flanking an edge of the at leastone expandable mirror 310 wherein the reflective surface of the sidemirrors 310 a adds to the total reflective area of the at least oneexpandable mirror 310. The additional reflective area can increase theamount of solar energy generated from the additional amount of sunlightreflected onto the PV cell 105.

The mirrors 110 are attached to the PV cell 105 via the hydraulicactuator 115 and the DC motor 120. The hydraulic actuator 115 isattached to the PV cell 105 at a predetermined location, for example onthe side of the PV cell 105 panel, on a first end. On a second end ofthe hydraulic actuator 115, the DC motor 120 is attached. The mirrors110 are attached to the DC motor 120 at a central point along an edge ofthe mirrors 110 such that the DC motor 120 can rotate the mirrors 110 ina clock-wise or counter-clock-wise rotation, or a mix of both directionswherein the rotation switches after a predetermined length of time. Therotation speed can be programmed to rotate at varying rotations perminute (RPM), for example less than 1 RPM, 100 RPM, or 5,000 RPM. Thehydraulic actuator 115 can be configured to extend or retract based onan amount of fluid received from or pumped out via the actuator pump125. This extension or retraction can increase or decrease the distanceof the mirrors 110 from the top surface of the PV cell 105. The mirrors110 can be connected to the PV cell 105 on both ends via the hydraulicactuator 115 and DC motor 120.

In an alternative embodiment, the mirrors 110 can be connected to the PVcell 105 on one end via the hydraulic actuator 115 and DC motor 120 andon an opposite end connected via a hydraulic actuator 115 without the DCmotor 120.

FIG. 2B illustrates another attachment configuration according to one ormore aspects of the disclosed subject matter. In another embodiment,each of the mirrors 110 can be connected to the PV cell 105 via twohydraulic actuators 115 without the DC motor 120. By varying theextension of each hydraulic actuator 115, the mirrors 120 can beadjusted to a predetermined optimal position to reflect the incidentsunlight onto the PV cell 105 based on the location of the sun.

The heat exchanger 130 is disposed below the PV cell 105 and thermallycoupled to the bottom surface of the PV cell 105. In order to maintainoptimal operational temperatures of the PV cell 105, the heat exchanger130 can be filled with a fluid and configured to transfer heat betweenthe PV cell 105 and the fluid. The fluid can be separated from the PVcell 105 by a wall or in direct contact with the PV cell 105 forenhanced thermal coupling. The heat exchanger 130 can include an inlet,a serpentine channel network for the fluid to flow through, and anoutlet for the fluid to exit. The fluid can be circulated from the heatexchanger 130 and into the radiator 140 via the fluid pump 135, whereinthe heat exchanger 130, fluid pump 135, and radiator 140 are connect bytubing. The radiator 140 can be configured to cool the hot fluid pumpedin from the heat exchanger 130 via a series of channels where the hotfluid flows through and is cooled by the air. In alternativeembodiments, the heat exchanger 130 can be a shell and tube heatexchanger, a plate heat exchanger, a plate and shell heat exchanger, ora plate fin heat exchanger.

The actuator pump 125 is also connected to the heat exchanger 130. Fluidfrom the heat exchanger 130 can be pumped into the hydraulic actuator115 via the actuator pump 125 in order to extend the hydraulic actuator115 and raise the height of the mirrors 110. Fluid from the heatexchanger 130 can also be withdrawn from the hydraulic actuator 115 viathe actuator pump 125 in order to decrease the height of the mirrors110. Integrating the actuator pump 125 into the heat exchanger 130increases the cooling capacity due to the increased volume of fluid inthe apparatus.

During the course of the day, the sun moves from sunrise along thehorizon to a peak and back down to the horizon at sunset. Sunlightincludes two main components which can be termed the direct beam, whichcarries a majority of the solar energy, and the diffuse sunlight,carrying the remainder. Energy contributed by the direct beam sunlightdrops off with the cosine of the angle between the incoming light andthe plane of the PV cell 105. If the PV cell 105 is oriented on asurface, for example a roof, wherein the plane of the PV cell 105 isparallel or nearly parallel with the ground, the PV cell 105 will notreceive as much direct beam sunlight during sunrise and sunset ascompared to when the sun is disposed overhead at its peak position. Asillustrated in FIG. 2A, according to one or more aspects of thedisclosed subject matter, the sun tracking device can be configured todetermine the position of the sun and instruct the DC motor 120 torotate the mirrors 110 in order to reflect the direct beam sunlight ontothe PV cell 105. For example, the mirrors 110 can be rotated such thatsunlight is reflected onto the PV cell 105 wherein the reflected raysare perpendicular to the top surface of the PV cell 105. During thesun's movement from horizon to peak, a shadow behind the mirrors 110 canform and lead to a net decrease in the energy production of the PV cell105 as compared to if the mirrors 110 were to reflect sunlight onto thePV cell 105. FIG. 4A illustrates an example orientation to reduce theshadow of the mirrors 110 according to one or more aspects of thedisclosed subject matter. At a predetermined sun position, the mirrors110 can rotate to an orientation wherein the shadow from the thicknessof the mirrors 110 is reduced to a minimum, for example the mirrors 110can rotate such that the plane of the mirrors 110 is parallel to thedirection of the direct beam sunlight.

As illustrated in FIG. 4B according to one or more aspects of thedisclosed subject matter, upon sunset or determination by the PV cell105 that the weather is not optimal for energy generation, for exampleif energy generation does not exceed a predetermined threshold, themirrors 110 can be rotated to a parallel orientation relative to the topsurface of the PV cell and laid flat to protect the surface from debris,such as water, sand, ice, and other foreign materials. The mirrors 110can be disposed above the top surface and moved closer to the topsurface until the mirrors 110 are in contact with the PV cell 110 topsurface.

The PV cell 105 can also be configured to detect the presence ofaccumulated debris, such as water, sand, ice, and other foreignmaterials, on the PV cell 105 surface. For example, the PV cell 105 candetermine its energy generation based on the amount of receivedsunlight, for example via one or more sensors, and a predeterminedthreshold of decreased energy generation can trigger a cleaningprocedure. FIG. 4C illustrates an example orientation for the cleaningprocedure according to one or more aspects of the disclosed subjectmatter. The cleaning procedure can include repositioning the mirrors 110to a predetermined distance away from the top surface of the PV cell 105and rotating the mirrors 110 at high speed, for example 100 RPM or 5,000RPM, in order to generate turbulent air flow. The resulting turbulentair can clear the PV cell 105 surface of debris, such as water, sand,ice, and other foreign materials, and recover operational efficiency.Thus, an optimal design of the mirrors 110 can be determined whereinstructural integrity of the mirrors 110 is maintained for cleaningevents where the mirrors 110 experience elevated forces that could leadto deformation, for example centripetal force, while being as thin aspossible to reduce the shadow resulting from the thickness of themirrors 110.

FIG. 4D illustrates another example orientation for the cleaningprocedure according to one or more aspects of the disclosed subjectmatter. In an alternative embodiment, the mirrors 110 can clean thesurface of the PV cell 105 via alternating movements away from andtowards the surface of the PV cell 105. The plane of the mirrors 110 canbe rotated to a nearly parallel orientation relative to the plane of thePV cell 105 and the hydraulic actuator 115 can be configured to increaseor decrease the distance of the mirrors 110 from the top surface of thePV cell 105. For example, the PV cell 105 can be oriented nearlyparallel to the ground and the mirrors 110 can start at a height justbarely above the surface of the debris, such as 10 cm above the surface,and the hydraulic actuator 115 can increase the height of the mirrors110. After reaching a predetermined height, the hydraulic actuator 115can decrease the height of the mirrors 110. The motion of the heightincrease and decrease can induce a pressure difference between the twosides of the mirrors 110 such that turbulent air flow is created. Thisturbulent air flow can cause the debris deposited on the surface of thePV cell 105 to move and fall off. The cycle of increasing and decreasingthe height can be repeated until a predetermined operational efficiencyhas been recovered.

An advantage of the PV system 110 is that the mirrors 110 can be rotatedto track the sun as compared to rotating the entire PV cell 105.Rotating the entire PV cell 105 results in higher energy consumption dueto the heavier payload as compared to the lightweight mirrors 110.Additionally, the mirrors 110 can be configured to clean the PV cell 105before, during, or after operation such that maximum efficiency inenergy generation is maintained. The mirrors can also lay flat toprotect the PV cell 105 during times of inclement weather, such as rainor sandstorms.

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made without departingfrom the spirit and scope of this disclosure. For example, preferableresults may be achieved if the steps of the disclosed techniques wereperformed in a different sequence, if components in the disclosedsystems were combined in a different manner, or if the components werereplaced or supplemented by other components.

The foregoing discussion describes merely exemplary embodiments of thepresent disclosure. As will be understood by those skilled in the art,the present disclosure may be embodied in other specific forms withoutdeparting from the spirit or essential characteristics thereof.Accordingly, the disclosure is intended to be illustrative, but notlimiting of the scope of the disclosure, as well as the claims. Thedisclosure, including any readily discernible variants of the teachingsherein, defines in part, the scope of the foregoing claim terminologysuch that no inventive subject matter is dedicated to the public.

1-7. (canceled) 8: A method of harvesting sunlight in a photovoltaicsystem, comprising: determining, via circuitry of a sun tracker of aphotovoltaic cell, an angle and an intensity of incident sunlight,wherein the photovoltaic cell includes a top surface configured togenerate electrical energy from the incident sunlight and a bottomsurface configured to thermally dispel heat generated by thephotovoltaic cell; adjusting a height of at least one mirror based onthe angle and the intensity of the incident sunlight such that theincident light is reflected by a reflective surface of the at least onemirror onto the top surface of the photovoltaic cell, wherein the atleast one mirror is disposed adjacent to the top surface of thephotovoltaic cell; adjusting a rotation angle of the at least one mirrorbased on the angle and the intensity of the incident sunlight such thatthe incident light is reflected by the reflective surface of the atleast one mirror onto the top surface of the photovoltaic cell;generating, via the top surface of the photovoltaic cell, electricalenergy from the incident sunlight that is reflected onto the top surfaceof the photovoltaic cell by the reflective surface of the at least onemirror; and dispelling, via the bottom surface of the photovoltaic cell,heat generated by the photovoltaic cell. 9: The method of 8, furthercomprising: detecting, using the photovoltaic cell, that the intensityof the incident sunlight is below a predetermined threshold; adjusting,using the plurality of actuators, the height of the at least one mirror;and rotating, using the motor, the at least one mirror to induceturbulent air flow to clean the top surface of the photovoltaic cell ofany deposited foreign matter.